Google's Android operating system is the number one OS for smartphones in the US, according to a new study from Nielsen. The results from June 2011 show that Android is now in 38 percent of all smartphones sold in the country. That's followed by Apple's iOS operating system with 28 percent and RIM's Blackberry OS at 20 percent. Microsoft's Windows Mobile OS combined with the more recent Windows Phone 7 take up 9 percent of the smartphone market. HP's WebOS and Nokia's Symbian operating system are tied with 2 percent.

While Android is number one in operating systems, Apple is the largest hardware maker for smartphones in the United States thanks to the fact that the iPhone is the only smartphone that uses the iOS platform. It now controls 28 percent of the US smartphone market. RIM also controls 20 percent of the smartphone hardware market for the same reason; the Blackberry OS can only be found on RIM's phones.

HTC is tied with RIM in terms of smartphone hardware; its Android based phones take up 14 percent of the market and its Windows Phone products control another 6 percent of the market. Motorola's Android phones hold onto 11 percent of the smartphone hardware market while Samsung's combined number of Android and Windows Phone devices now have 10 percent of the market.

While Windows Phone 7 is on the low end of both the hardware and software smartphone numbers in this latest Nielsen survey, those numbers are likely to change when the first "Mango" phones are released later this fall.